usr/src/sys.386bsd/isofs/isofs_node.c

/*
 * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)isofs_inode.c
 */

#include "param.h"
#include "systm.h"
#include "mount.h"
#include "proc.h"
#include "file.h"
#include "buf.h"
#include "vnode.h"
#include "kernel.h"
#include "malloc.h"

#include "iso.h"
#include "isofs_node.h"

#define INOHSZ  512
#if     ((INOHSZ&(INOHSZ-1)) == 0)
#define INOHASH(dev,ino)        (((dev)+(ino))&(INOHSZ-1))
#else
#define INOHASH(dev,ino)        (((unsigned)((dev)+(ino)))%INOHSZ)
#endif

union iso_ihead {
        union  iso_ihead *ih_head[2];
        struct iso_node *ih_chain[2];
} iso_ihead[INOHSZ];

int prtactive;  /* 1 => print out reclaim of active vnodes */

/*
 * Initialize hash links for inodes.
 */
isofs_init()
{
        register int i;
        register union iso_ihead *ih = iso_ihead;

#ifndef lint
        if (VN_MAXPRIVATE < sizeof(struct iso_node))
                panic("ihinit: too small");
#endif /* not lint */
        for (i = INOHSZ; --i >= 0; ih++) {
                ih->ih_head[0] = ih;
                ih->ih_head[1] = ih;
        }
}

/*
 * Look up a ISOFS dinode number to find its incore vnode.
 * If it is not in core, read it in from the specified device.
 * If it is in core, wait for the lock bit to clear, then
 * return the inode locked. Detection and handling of mount
 * points must be done by the calling routine.
 */
iso_iget(xp, ino, ipp, isodir)
        struct iso_node *xp;
        ino_t ino;
        struct iso_node **ipp;
        struct iso_directory_record *isodir;
{
        dev_t dev = xp->i_dev;
        struct mount *mntp = ITOV(xp)->v_mount;
        extern struct vnodeops isofs_vnodeops, spec_inodeops;
        register struct iso_node *ip, *iq;
        register struct vnode *vp;
        struct vnode *nvp;
        struct buf *bp;
        struct dinode *dp;
        union iso_ihead *ih;
        int i, error;
        struct iso_mnt *imp;

        ih = &iso_ihead[INOHASH(dev, ino)];
loop:
        for (ip = ih->ih_chain[0];
             ip != (struct iso_node *)ih;
             ip = ip->i_forw) {
                if (ino != ip->i_number || dev != ip->i_dev)
                        continue;
                if ((ip->i_flag&ILOCKED) != 0) {
                        ip->i_flag |= IWANT;
                        sleep((caddr_t)ip, PINOD);
                        goto loop;
                }
                if (vget(ITOV(ip)))
                        goto loop;
                *ipp = ip;
                return(0);
        }
        /*
         * Allocate a new inode.
         */
        if (error = getnewvnode(VT_ISOFS, mntp, &isofs_vnodeops, &nvp)) {
                *ipp = 0;
                return (error);
        }
        ip = VTOI(nvp);
        ip->i_vnode = nvp;
        ip->i_flag = 0;
        ip->i_devvp = 0;
        ip->i_diroff = 0;
        ip->i_lockf = 0;
        /*
         * Put it onto its hash chain and lock it so that other requests for
         * this inode will block if they arrive while we are sleeping waiting
         * for old data structures to be purged or for the contents of the
         * disk portion of this inode to be read.
         */
        ip->i_dev = dev;
        ip->i_number = ino;
        insque(ip, ih);
        ISO_ILOCK(ip);

        ip->iso_reclen = isonum_711 (isodir->length);
        ip->iso_extlen = isonum_711 (isodir->ext_attr_length);
        ip->iso_extent = isonum_733 (isodir->extent);
        ip->i_size = isonum_733 (isodir->size);
        bcopy (isodir->date, ip->iso_time, sizeof ip->iso_time);
        ip->iso_flags = isonum_711 (isodir->flags);
        ip->iso_unit_size = isonum_711 (isodir->file_unit_size);
        ip->iso_interleave_gap = isonum_711 (isodir->interleave);
        ip->iso_volume_seq = isonum_723 (isodir->volume_sequence_number);
        ip->iso_namelen = isonum_711 (isodir->name_len);

        /*
         * Initialize the associated vnode
         */
        vp = ITOV(ip);

        if (ip->iso_flags & 2)
                vp->v_type = VDIR;
        else
                vp->v_type = VREG;

        imp = VFSTOISOFS (mntp);

        if (ino == imp->root_extent)
                vp->v_flag |= VROOT;
        /*
         * Finish inode initialization.
         */
        ip->i_mnt = imp;
        ip->i_devvp = imp->im_devvp;
        VREF(ip->i_devvp);
        *ipp = ip;
        return (0);
}

/*
 * Unlock and decrement the reference count of an inode structure.
 */
iso_iput(ip)
        register struct iso_node *ip;
{

        if ((ip->i_flag & ILOCKED) == 0)
                panic("iso_iput");
        ISO_IUNLOCK(ip);
        vrele(ITOV(ip));
}

/*
 * Last reference to an inode, write the inode out and if necessary,
 * truncate and deallocate the file.
 */
isofs_inactive(vp, p)
        struct vnode *vp;
        struct proc *p;
{
        register struct iso_node *ip = VTOI(vp);
        int mode, error = 0;

        if (prtactive && vp->v_usecount != 0)
                vprint("isofs_inactive: pushing active", vp);

        ip->i_flag = 0;
        /*
         * If we are done with the inode, reclaim it
         * so that it can be reused immediately.
         */
        if (vp->v_usecount == 0 /* && ip->i_mode == 0 */)
                vgone(vp);
        return (error);
}

/*
 * Reclaim an inode so that it can be used for other purposes.
 */
isofs_reclaim(vp)
        register struct vnode *vp;
{
        register struct iso_node *ip = VTOI(vp);
        int i;

        if (prtactive && vp->v_usecount != 0)
                vprint("isofs_reclaim: pushing active", vp);
        /*
         * Remove the inode from its hash chain.
         */
        remque(ip);
        ip->i_forw = ip;
        ip->i_back = ip;
        /*
         * Purge old data structures associated with the inode.
         */
        cache_purge(vp);
        if (ip->i_devvp) {
                vrele(ip->i_devvp);
                ip->i_devvp = 0;
        }
        ip->i_flag = 0;
        return (0);
}

/*
 * Lock an inode. If its already locked, set the WANT bit and sleep.
 */
iso_ilock(ip)
        register struct iso_node *ip;
{

        while (ip->i_flag & ILOCKED) {
                ip->i_flag |= IWANT;
                if (ip->i_spare0 == curproc->p_pid)
                        panic("locking against myself");
                ip->i_spare1 = curproc->p_pid;
                (void) sleep((caddr_t)ip, PINOD);
        }
        ip->i_spare1 = 0;
        ip->i_spare0 = curproc->p_pid;
        ip->i_flag |= ILOCKED;
}

/*
 * Unlock an inode.  If WANT bit is on, wakeup.
 */
iso_iunlock(ip)
        register struct iso_node *ip;
{

        if ((ip->i_flag & ILOCKED) == 0)
                vprint("iso_iunlock: unlocked inode", ITOV(ip));
        ip->i_spare0 = 0;
        ip->i_flag &= ~ILOCKED;
        if (ip->i_flag&IWANT) {
                ip->i_flag &= ~IWANT;
                wakeup((caddr_t)ip);
        }
}